[HTML][HTML] Nusinersen versus sham control in later-onset spinal muscular atrophy

E Mercuri, BT Darras, CA Chiriboga… - … England Journal of …, 2018 - Mass Medical Soc
E Mercuri, BT Darras, CA Chiriboga, JW Day, C Campbell, AM Connolly, ST Iannaccone…
New England Journal of Medicine, 2018Mass Medical Soc
Background Nusinersen is an antisense oligonucleotide drug that modulates pre–
messenger RNA splicing of the survival motor neuron 2 (SMN2) gene. It has been
developed for the treatment of spinal muscular atrophy (SMA). Methods We conducted a
multicenter, double-blind, sham-controlled, phase 3 trial of nusinersen in 126 children with
SMA who had symptom onset after 6 months of age. The children were randomly assigned,
in a 2: 1 ratio, to undergo intrathecal administration of nusinersen at a dose of 12 mg …
Background
Nusinersen is an antisense oligonucleotide drug that modulates pre–messenger RNA splicing of the survival motor neuron 2 (SMN2) gene. It has been developed for the treatment of spinal muscular atrophy (SMA).
Methods
We conducted a multicenter, double-blind, sham-controlled, phase 3 trial of nusinersen in 126 children with SMA who had symptom onset after 6 months of age. The children were randomly assigned, in a 2:1 ratio, to undergo intrathecal administration of nusinersen at a dose of 12 mg (nusinersen group) or a sham procedure (control group) on days 1, 29, 85, and 274. The primary end point was the least-squares mean change from baseline in the Hammersmith Functional Motor Scale–Expanded (HFMSE) score at 15 months of treatment; HFMSE scores range from 0 to 66, with higher scores indicating better motor function. Secondary end points included the percentage of children with a clinically meaningful increase from baseline in the HFMSE score (≥3 points), an outcome that indicates improvement in at least two motor skills.
Results
In the prespecified interim analysis, there was a least-squares mean increase from baseline to month 15 in the HFMSE score in the nusinersen group (by 4.0 points) and a least-squares mean decrease in the control group (by –1.9 points), with a significant between-group difference favoring nusinersen (least-squares mean difference in change, 5.9 points; 95% confidence interval, 3.7 to 8.1; P<0.001). This result prompted early termination of the trial. Results of the final analysis were consistent with results of the interim analysis. In the final analysis, 57% of the children in the nusinersen group as compared with 26% in the control group had an increase from baseline to month 15 in the HFMSE score of at least 3 points (P<0.001), and the overall incidence of adverse events was similar in the nusinersen group and the control group (93% and 100%, respectively).
Conclusions
Among children with later-onset SMA, those who received nusinersen had significant and clinically meaningful improvement in motor function as compared with those in the control group. (Funded by Biogen and Ionis Pharmaceuticals; CHERISH ClinicalTrials.gov number, NCT02292537.)
The New England Journal Of Medicine